Shovel loaders with chain operated bucket structure



Jan. 5, 1965 s. E. ERIKSSON 3,164,273

SHOVEL. LOADERS WITH CHAIN OPERATED BUCKET STRUCTURE Filed April 10, 1962 4 Sheets-Sheet 1 Fig] Jan. 5, 1965 s. E. ERIKSSON 3,164,273

SHOVEL LOADERS WITH CHAIN OPERATED BUCKET STRUCTURE Filed April 10, 1962 4 Sheets-Sheet 2 L 1 T? /5 M 5 INVENTOR.

T I l l 4 I 26 25 26 /3 Jan. 5, 1965 s. E. ERIKSSON 3,164,273

} SHOVEL LOADERS WITH CHAIN OPERATED BUCKET STRUCTURE Filed April 10, 1962 4 Sheets-Sheet 5 INVENTOR.

1965 s. E. ERIKSSON 3, ,2

SHOVEL LOADERS WITH CHAIN OPERATED BUCKET STRUCTURE Filed April 10, 1962 4 Sheets-Sheet 4 Fig. /0

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$4M z gVENTOR BY. CM

United States Patent Ofifice EJ542 73 Patented Jan. 5, 1965 3,164,273 SHOVEL LOADERS WITH CHAIN OPERATED BUCKET STRUCTURE Sven Erik Eriksson, Orebro, Sweden, assignor to Atlas Copco Aktiebolag, Nacka, Sweden, a corporation of Sweden Filed Apr. 10, 1962, Ser. No. 186,560 13 Claims. (Cl. 214-131) This invention relates to shovel loaders of the type having a bucket structure which is movable on a frame from a digging position to an elevated discharge position by means of one or more chains. Loaders of this type are commonly used in connection with mining and tunneling and other underground work for loading rock or ore or coal or other material into a container or receptacle which may be provided and carried by the loader itself or which may be attached to or associated with the loader. Partic ularly in connection with loading of blasted rock and in connection with loaders in which the bucket structure is pivoted on the loader the chains for operating the bucket structure are subjected to severe stresses and shocks. Such shocks frequently occur when the bucket structure is dumped and the dumping movement is counteracted by changing the direction of operation of the bucket structure operating motor. The chain or chains connecting the bucket structure with the motor is not per se sufiiciently resilient to provide a desirable reduction of the shock stresses produced in the bucket structure operating mechanism, and one embodiment of the present invention is to provide a bucket structure operating mechanism which is more resilient than such operating mechanisms known so far in order to reduce shock stresses in the chain and associated parts. A further object of the invention is to incorporate resilient means in the bucket structure operating mechanism which have a large damping or cushioning capacity. A still further object of the invention is to provide resilient means which in a simple manner may be incorporated in shovel loaders of conventional design and which are simple and easy to assemble and to disassemble.

Other objects and features of the invention will appear from the following specification and the accompanying drawings, it being understood, however, that the invention is not limited to the illustrated embodiments but may be modified in several different ways within the scope of the claims.

In the drawings, FIG. 1 is a perspective side view of a pivoted bucketshovel loader in which the bucket discharges into a container carried by the loader. FIG. 2 is a partial side view and vertical longitudinal section of the front portion of the loader according to FIG. 1 showing the bucket operating mechanism. FIG. 3 is an exploded perspective view on a larger scale of a bracket carrying an idle roller over which the bucket operating chain is carried. FIG. 4 shows a bracket similar to the bracket illustrated in FIG. 3 in perspective view and provided with a resiliently mounted roller, and FIG. 5 is a horizontal cross section on a plane through the roller axis as indicated by VV in FIG. 4. FIG. 6 is an exploded perspective view of a modification of the bracket according to FIG. 3. FIG. 7 is a perspective view of the connection between the chain and the bucket structure, and

FIG. 8 is a detail section on a vertical plane on line VIIIVIII in FIG. 7. FIG. 9 illustrates a motor driven chain reel, and FIG. 10 is an exploded perspective View of the reel structure in FIG. 9.

The shovel loader illustrated in FIGS. 1 and 2 consists of a frame structure 1 which is movable on four wheels 2 operated by a not illustrated traction motor under control of a control lever 3. The loader is provided with a receptacle 4 which by not illustrated power cylinders may be tilted and discharged rearwardly or to the side of the loader as is conventional in machines of this type. The rear wall or the side wall of the receptacle is then opened to permit material to flow out of the receptacle.

At the front end of the frame a bucket structure comprising a bucket 5 and arms 6 is pivotally carried on large pivots 7 at the front portion of the frame 1. The bucket structure 5, 6 is swingable from the illustrated digging or loading position shown in FIGS. 1 and 2 to an elevated discharge position in which the contents of the bucket is discharged into the receptacle 4 and which com prises a swinging movement through about 180 until the bucket structure is arrested by a bundle of leaf springs 8 cooperating with the arms 6' and attached to the front end of the frame 1. The bucket structure is moved from digging position to discharge position by means of a link chain 9 which may be wound on and secured to a hub 52 of a chain reel or power take-up mechanism 10 driven by a suitable reversible motor 11 controlled by a lever 51.

The chain 9 is connected to the bucket structure by means of a bracket bolted to the bucket 5 and is carried over a roller 13 journalled on a shaft 14 carried by a bracket 15 which may be secured to the front portion of the frame 1 in various manners as will be described hereinbelow and forming a break point dividing chain 9 into two segments meeting at an angle. In the embodiment of the invention illustrated in FIG. 3 the bracket 15 has a base plate 16 which is mounted on 4 large rubber cushioning blocks 17 of yielding resilient rubber material which are fitted in two channels 18 by means of bolts 19 screwed and secured in threaded holes 20 in two side members 21, which form a part of the front end of the frame 1. The rubber blocks 17 permit the bracket 15 to yield somewhat when shock stresses occur in the chain 9 carried over the roller 13. 7

FIGS. 4 and 5' shows a modification of the bracket 15 in F16 3 which involves a resilient mounting of the roller .13 on the shaft 14. For this purpose the shaft 14 is carried through a bushing comprising an inner and an outer steel tube 22, 23 between which a heavy cylindrical soft rubber cushioning bushing 24 is secured preferably by being vulcanized to the tubes 22 and 23. The tube 23 is carried in antif-riction bearings 25 which carry the roller 13 and which are kept in place between the bracket members 15 by spacers 26. The rubber bushing 2 4 adds resiliency to the mounting of the roller 13 which helps to take up shock stresses produced in the chain 9. However, if the rubber bushing 24 is given sufficient dimensions, the rubber blocks 17 may sometime be dispensed with. I

In the modification of the bracket 15 illustrated in FIG. 6 the bracket is carried by a base plate 27 which forms a portion of a hinge swingable on bolts 28 carried by hinge members 29 secured to the front portion of the frame 1. Cotter pins 30 keep the bolts 28 in place. The base plate 27 is stepped as at 31 and rests with the stepped portion 31 on a large rectangular rubber block 32 mounted on an angle iron 33. The base plate 27 and the resilient rubber cushioning block 32 and the angle iron 33 is held against the side members 21 of the frame by means of bolts 34 and nuts 35 locked on said bolts. It is obvious that the provision Oif the soft rubber block 32 gives the bracket 15 a limited ability to yield resiliently when a shock stress occurs in the chain 9. A roller 13 as shown in FIGS. 3 or 45 may of course be provided and carried by the bracket 15 by means of a bolt extending through the holes 36 in the bracket members.

Resiliency may also be built into the bucket operating mechanism by provision of .a bracket 37 for mounting J the chain 9 to the bucket 5, as illustrated in FIGS. 7 and 8. The chain 9 is connected to the upright bracket member by a bolt 38 and the bracket member has a base plate 39 which is resiliently held against the bucket by four locked bolts 40 provided with lock nuts 41 and a set of Belleville cushioning springs 4-2 interposed between the nuts 41 and'the base plate 39, so that the base plate 39 may yield slightly upon the occur-ance of shock stresses in the chain 9.

FIGS. 9 and show a suitable chain reel 16 which may alone or in connection with some of the above described means provide the necessary resiliency to the bucket operating mechanism. For this purpose the chain reel 10 is provided with a rim 43 having a number of radially extending lugs 44. The rim 43 and the lugs 44 cooperate witha disc 45 having a number of corresponding lugs 46 extending radially on one side of the disc 45 and fitting in between the lugs 44 when the disc 45 is assembled into the rim 43. The lugs 46 do only fill out a portion of the space between the lugs 44 and the rest of the space is filled out by a number of segment shaped rubber cushioning blocks 47 of a yielding type of resilient rubber, so that the disc 45 may be twisted slightly with regard to the rim 43 on the reel 10. The reel 10 is driven from the motor 11 over a splined shaft 48 which meshes with a grooved opening 49 in the disc 45. A bolt and washer 50 is provided for securing the disc on the end of the shaft 48. Obviously the rubber blocks 47 provide a resilient force transmission between the bucket operating motor and the chain 9, which may be secured to hub of the reel 10; in conventional manner.

The above described resilient means may be used alone or in combination in order to provide a desired elasticity in the chain connection between the motor 11 and the bucket structures 5, 6. Exhaustive tests have shown that such resilient means vastly increase the useful life of the chain 9 loaders of the pivoted bucket type.

, What I claim is:

1. In an arrangement of the character described for providing shock-absorbing resiliency in a link chain drive for shovel loading apparatus having a bucket movable from a loading position to a discharge position, the combination which comprises a nonsresilient link chain, means for connecting one end thereof to said bucket, power takeup means on said apparatus and connected to said chain adjacent the end thereof opposite to said bucket for taking up said chain and moving said bucket from said loadingto said discharge position, means forming a break point for said chain at a point therealong between said take-up means and said bucket and dividing said chain into two segments which meet at an angle of less than 180, and resilient means associated with said chain and at least one of said power take-up and break point and bucket connection means for providing shock-absorbing resiliency to both said segments of said chain.

' 2. An arrangement as recited in claim 1 in which said resilient means is associated with said means forming said break point, which in turn comprises idler roller means mounted on said apparatus for limited movement with respect thereto and resilient cushioning means disposed between said idler roller means and said apparatus for providing said shock absorbing resiliency.

3. An arrangement .as recited in claim 1 in which said resilient means is associated with said means forming said break point, which in turn comprises a freely rotating idler roller and a shaft therefor, bracket means for mounting said shaft on said apparatus, and resilient cushioning bushing means on said shaft for providing said shockabsorbing resiliency.

4. An arrangement as recited in claim 3 in which said shaft comprises two coaxial metal bushings of ditferent diameters permitting limited radial movement of said roller with respect to the smaller of said bushings, and in which said'resilient cushioning means is disposed between said coaxial bushings.

5. An arrangement as recited in claim 1 in which said resilient means is associated with said means forming said break point, which in turn comprises idler means extending outwardly from said apparatus, a base plate for mounting said idler means on said apparatus, said base plate being pivoted to said apparatus along one edge of said plate for limited swinging movement with respect thereto, and resilient cushioning means disposed between said base plate and said apparatus adjacent the edge of said base plate opposite to said pivoted edge.

6. An arrangement as recited in claim 1 in which said resilient means is associated with said power take-up means, which in turn comprises rotating means for taking up said chain and drawing it over said break point to move said bucket from said loading position to said discharge position, drive means for rotating said take-up means, and a resilient cushioning connection between said drive means and said take-up means.

7. An arrangement as recited in claim 6 in which said rotating take-up means is a reel for said chain, and in which said resilient cushioning connection is disposed within said reel.

8. An arrangement as recited in claim 1 in which said resilient means is associated with said means connecting said chain to said bucket and includes resilient cushioning members disposed between said chain and said bucket for providing said shock-absorbing resiliency.

9. An arrangement as recited in claim 8 in which said means for connecting said chain to said bucket includes a connecting bracket engaging one end of said chain, fastening means for affixing said bracket to said bucket for limited movement with respect thereto, and in which said resilient cushioning members are disposed on said bracket and around said fastening means.

10. In an arrangement of the character described for providing shock-absorbing resiliency in a link chain drive for shovel loading apparatus having a bucket movable from a loading position to a discharge position, the combination which comprises a non-resilient link chain, means for connecting one end thereof to said bucket, power take-up means on said apparatus and connected to said chain adjacent the end thereof opposite to said bucket for taking up said chain and moving said bucket from said loading to said discharge position, idler means extending outwardly from said apparatus between said bucket and said take-up means for engaging said chain forming a break point therefor over which said chain is drawn by said take-up means, and resilient cushioning mean-s associated with said idler means effecting limited movement thereof with respect to said apparatus for providing shock-absorbing resiliency to said chain for absorbing shocks imparted thereto by movement of said bucket and said take-up means.

11. An arrangement as recited in claim 10 in which additional shock-absorbing resilient cushioning means for said chain are provided in said means for connecting one end of said chain to said bucket.

12. An arrangement as recited in claim 10 in which additional shock-absorbing resilient cushioning means for said chain are provided in said power take-up means.

13. An arrangement as recited in claim 10 in which additional shock-absorbing resilient cushioning means for said chain are provided in both said means for connecting said chain to said bucket and said power take-up means.

References Cited in the tile of this patent UNITED STATES PATENTS 1,791,979 Sharp Feb. 10, 1931 2,109,053 Searles Feb. 22, 1938 2,179,469 Germonprez Nov. 7, 1939 2,399,414 Wells et al. Apr. 30, 1946 2,461,973 Fitch Feb. 15, 1949 2,588,158 Peirce Mar. 4, 1952 2,752,053 Schwartz June 26, 1956 

1. IN AN ARRANGEMENT OF THE CHARACTER DESCRIBED FOR PROVIDING SHOCK-ABSORBING RESILIENCY IN A LINK CHAIN DRIVE FOR SHOVEL LOADING APPARATUS HAVING A BUCKET MOVABLE FROM A LOADING POSITION TO A DISCHARGE POSITION, THE COMBINATION WHICH COMPRISES A NON-RESILIENT LINK CHAIN, MEANS FOR CONNECTION ONE END THEREOF TO SAID BUCKET, POWER TAKEUP MEANS ON SAID APPARATUS AND CONNECTED TO SAID CHAIN ADJACENT THE END THEREOF OPPOSITE TO SAID BUCKET FOR TAKING UP SAID CHAIN AND MOVING SAID BUCKET FROM SAID LOADING TO SAID DISCHARGE POSITION, MEANS FORMING A BREAK POINT FOR SAID CHAIN AT A POINT THEREALONG BETWEEN SAID TAKE-UP MEANS AND SAID BUCKET AND DIVIDING SAID CHAIN INTO TWO SEGMENTS WHICH MEET AT AN ANGLE OF LESS THAN 180*, AND RESILIENT MEANS ASSOCIATED WITH SAID CHAIN AND AT LEAST ONE OF SAID POWER TAKE-UP AND BREAK POINT AND BUCKET CONNECTION MEANS FOR PROVIDING SHOCK-ABSORBING RESILIENCY TO BOTH SAID SEGMENTS OF SAID CHAIN. 